IP trie树接口

自己实现了一个IP trie树接口.

在这里保存一下，方便备份以后使用，同时欢迎纠错和交流，希望有大神能指教更高效的算法.

1.头文件如下(iptrie.h)

#ifndef _IP_TRIE_H_
#define _IP_TIRE_H_

#define SPLIT_SIGN "."
#define IP_BINARY_LEN 32

typedef struct ip_trie_node
{
    struct ip_trie_node *child[2]; //two child node
}ip_trie_node;

ip_trie_node *create_iptrie_node();

void insert_iptrie_node(ip_trie_node *root,char ip[]);

int select_iptrie_node(ip_trie_node *root,char ip[]);

#endif

2.c文件如下(iptrie.c)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "iptrie.h"

/*
 *name: itobinary
 *
 *param:
 * num: orignal number; binary_str: dest string; index: the binary str copy index
 *
 *return:
 * void
 */
void itobinary(int num,char binary_str[],int index)
{
    if(binary_str == NULL)
    {
        return;
    }

    int i,bit = 0x01;
    for(i = 0; i < 8; i++)
    {//conver integer to 8 bit binary str
        if((num & bit) != 0)
        {//oprater & is lower than != 
            binary_str[index + 7 - i] = '1';
        }
        else
        {
            binary_str[index + 7 - i] = '0';
        }
        
        bit <<= 1; //bit * 2
    }
}

/*
 *name: convert_ip_binary
 *
 *param:
 * ip:orign ip string; binary_str:dest binary string
 *
 *return:
 * void
 */
void convert_ip_binary(char ip[],char binary_str[])
{
    if(ip == NULL || binary_str == NULL)
    {
        return;
    }
    
    /*为确保正确性在进行转换之前可以进一步进行IP格式校验*/

    char *ip_sub = NULL;
    int i,index =0;
    
    ip_sub = strtok(ip,SPLIT_SIGN); //slit ip by .

    itobinary(atoi(ip_sub),binary_str,index);

    for(i = 0; i < 3; i++)
    {//need to ip legal detect to pretend error
        ip_sub = strtok(NULL,SPLIT_SIGN);
        
        index += 8;
        itobinary(atoi(ip_sub),binary_str,index);
    }

}

/*
 *name: create_iptrie_node
 *
 *return:
 * new ip trie node
 */
ip_trie_node *create_iptrie_node()
{
    ip_trie_node *node = (ip_trie_node *)calloc(1,sizeof(ip_trie_node));

    if(node == NULL)
    {
        perror("create ip trie node error -- calloc");
    }
    else
    {
        node->child[0] = NULL;
        node->child[1] = NULL;
    }

    return node;
}

/*
 *name: insert_iptrie_node
 *
 *param:
 * root: trie root; ip: orignal ip string
 * 
 *return:
 * void
 *
 *notice:
 * this function call strtok it will change input ip
 * so if input ip need to use at other position
 * you shold input a copy of ip
 */
void insert_iptrie_node(ip_trie_node *root,char ip[])
{
    if(root == NULL)
    {
        printf("trie have not init
");
        
        return;
    }

    if(ip == NULL)
    {
        return;
    }

    char binary_str[IP_BINARY_LEN + 1];
    int i,child_index;
    
    memset(binary_str,0,IP_BINARY_LEN + 1);
    
    convert_ip_binary(ip,binary_str); //to binary string

    for(i = 0; i < IP_BINARY_LEN; i++)
    {
        child_index = binary_str[i] - '0'; //child is 0 or 1
        if(root->child[child_index] == NULL)
        {
            root->child[child_index] = create_iptrie_node();
        }
        
        root = root->child[child_index];
    }
}

/*
 *name: select_iptrie_node
 *
 *param: 
 * root: trie root; ip: orignal ip string
 *
 *return:
 * 0 :not find; 1:find
 *
 *notice:
 * this function call strtok it will change input ip
 * so if input ip need to use at other position
 * you shold input a copy of ip
 */
int select_iptrie_node(ip_trie_node *root,char ip[])
{
    if(root == NULL)
    {
        printf("trie have not init
");
        return 0;
    }

    if(ip == NULL)
    {
        return 0;
    }

    int i;
    char binary_str[IP_BINARY_LEN + 1];

    memset(binary_str,0,IP_BINARY_LEN + 1);

    convert_ip_binary(ip,binary_str); //to binary string

    int child_index;
    for(i = 0; i < IP_BINARY_LEN; i++)
    {
        child_index = binary_str[i] - '0';
        
        if(root->child[child_index] == NULL)
        {
            return 0;
        }

        root = root->child[child_index];
    }

    return 1;
}

3.main.c如下(测试程序)

#include <stdio.h>
#include <stdlib.h>

#include "iptrie.h"


int main()
{
    char sip[16];
    char dip[16];
    int i = 0;
    int isfind = 0;
    ip_trie_node *root = create_iptrie_node();

    while(1)
    {
        printf("insert a ip:
");
        scanf("%s",sip);
        insert_iptrie_node(root,sip);
        
        printf("query a ip:
");
        scanf("%s",dip);
        isfind = select_iptrie_node(root,dip);
        if(isfind == 1)
        {
            printf("find
");
        }
        else
        {
            printf("not find
");
        }
    }
}

4.Makefile (linux下编译)

CC = gcc
CFLAG = -g

INC = -I./

target:Iptrie

Iptrie:iptrie.o main.c
    $(CC) $(CFLAG) $(INC) -o $@  $^

iptrie.o:iptrie.c
    $(CC) -c $<

clean:
    rm *.o Iptrie